public class TextBoxHelper

{

    public Color BackgroundColor = Colors.White; // 背景色

    public Color TextColor = Colors.Black; // 文字颜色

    public Color LinecodeBackground = Colors.Gainsboro; // 显示行号背景色

    public Color LinecodeColor = Colors.SteelBlue; // 显示行号文字色

    public FontFamily  fontFamily =  new FontFamily("Microsoft YaHei");  // 字体

    public double Fontsize = 12; // 字体大小

    public double Line_Height = 20; // 行高度

    public double Linecode_Width = 30; // 行号宽度

    public double Linecode_Interval = 5; // 行号右侧间隔

    public TextBox Editor;  // TextBox组件



    private ScrollTemplate scrollTemplate_TextBox;

    public Canvas Editor_Box;

    private TextBox Linemeasure;

    private Canvas Linenumber;



    /// <summary>

    /// 带行号的TextBox

    /// </summary>

    /// <param name="obj">父容器</param>

    /// <param name="x">位置 x</param>

    /// <param name="y">位置 y</param>

    /// <param name="width">宽度</param>

    /// <param name="height">高度</param>

    public void LinenumberEditor(Canvas obj, double x, double y, double width, double height)

    {

        Editor_Box = new Canvas()

        {

            Width = width + Linecode_Width,

            Height = height,

            Background = new SolidColorBrush(BackgroundColor),

            Clip = new RectangleGeometry(new Rect(0, 0, width, height))

        };

        Canvas.SetLeft(Editor_Box, x);

        Canvas.SetTop(Editor_Box, y);



        Editor = new TextBox()

        {

            Width = width - Linecode_Width,

            BorderThickness = new Thickness(0),

            TextWrapping = TextWrapping.Wrap,

            AcceptsReturn = true,

            FontFamily = fontFamily,

            FontSize = Fontsize,

            Foreground = new SolidColorBrush(TextColor),

            Background =Brushes.Transparent

        };

        Editor.TextChanged += Editor_TextChanged;

        TextBlock.SetLineHeight(Editor, Line_Height);

        Canvas.SetLeft(Editor, 30);



        WrapPanel text_panel = new WrapPanel()

        {

            Width = Editor.Width,

            Orientation = Orientation.Vertical,

        };

        text_panel.Children.Add(Editor);

        

        scrollTemplate_TextBox = new ScrollTemplate();

        scrollTemplate_TextBox.ScrollViewer.Background = Brushes.WhiteSmoke;

        scrollTemplate_TextBox.InitializeScrollViewer(Editor_Box, text_panel, Linecode_Width, 0, width- Linecode_Width, height, ScrollViewer_Type.Win10);

        scrollTemplate_TextBox.ScrollViewer.ScrollChanged += (s, e) => {

            GeneralTransform generalTransform = Editor.TransformToAncestor(Editor_Box);

            Point point = generalTransform.Transform(new Point(0, 0));

            Canvas.SetTop(Linenumber, point.Y);

        };

        scrollTemplate_TextBox.ScrollViewer.PreviewMouseDown += (s, e) => {

             obj.Dispatcher.BeginInvoke(DispatcherPriority.Background,

            (Action)(() => { Keyboard.Focus(Editor); }));

        };



        Linenumber = new Canvas()

        {

            Width = Linecode_Width,

            Height = height,

            Background = new SolidColorBrush(LinecodeBackground)

        };

        Editor_Box.Children.Add(Linenumber);



        TextBlock Linecode = new TextBlock()

        {

            Height = Line_Height,

            Width = Linecode_Width - Linecode_Interval,

            TextAlignment = TextAlignment.Right,

            Text = "1",

            FontFamily = fontFamily,

            FontSize = Fontsize,

            Foreground = new SolidColorBrush(LinecodeColor),

            Background = Brushes.Transparent

        };

        Linenumber.Children.Add(Linecode);



        Linemeasure = new TextBox()

        {

            Width = width - Linecode_Width,

            Height = 100,

            TextWrapping = TextWrapping.Wrap,

            BorderThickness = new Thickness(0),

            FontFamily = fontFamily,

            FontSize = Fontsize,

            Visibility = Visibility.Hidden

        };

        Canvas.SetLeft(Linemeasure, -x);

        Canvas.SetTop(Linemeasure, -1);

        obj.Children.Add(Linemeasure);



        Editor_Box.MouseDown += (s, e) => { Editor.Focus(); };

        obj.Children.Add(Editor_Box);

    }



    private void Editor_TextChanged(object sender, TextChangedEventArgs e)

    {

        if (Linenumber.Children.Count != Editor.LineCount)

        {

            if (Linenumber.Children.Count < Editor.LineCount)

            {

                for (int i = Linenumber.Children.Count; i < Editor.LineCount; i++)

                {

                    TextBlock Linecode = new TextBlock()

                    {

                        Height = Line_Height,

                        Width = Linecode_Width - Linecode_Interval,

                        TextAlignment = TextAlignment.Right,

                        FontFamily = fontFamily,

                        FontSize = Fontsize,

                        Foreground = new SolidColorBrush(LinecodeColor),

                        Background = Brushes.Transparent

                    };



                    Canvas.SetTop(Linecode, i * Line_Height);

                    Linenumber.Children.Add(Linecode);

                }

            }

            else

            if (Linenumber.Children.Count > Editor.LineCount)

            {

                for (int i = Linenumber.Children.Count-1 ; i > Editor.LineCount - 1; i--)

                {

                    Linenumber.Children.RemoveAt(i);

                }

            }



            for (int i = 0; i < Linenumber.Children.Count; i++)

            {

                (Linenumber.Children[i] as TextBlock).Text = "";

            }



            string[] split = Editor.Text.Split(new string[] { "\r\n" }, StringSplitOptions.None);

            int line = 0;

            for (int i = 0; i < split.Length; i++)

            {

                (Linenumber.Children[line] as TextBlock).Text = (i + 1).ToString();

                Linemeasure.Text = split[i];

                line += Linemeasure.LineCount;

            }

            Linenumber.Height = Editor.LineCount* Line_Height < Editor_Box.Height? Editor_Box.Height: Editor.LineCount * Line_Height;

        }

    }